Numerous kinds of industrial rubber materials and synthetic resin materials are known, and in particular, polyolefin-type vulcanized rubbers such as ethylene-propylene-diene copolymer rubbers (EPDM) and ethylene-propylene copolymer rubbers (EPM) as well as polyolefin-type synthetic resins such as polypropylene (PP) and polyethylene (PE) have been used in various industrial fields, as these are polymers with excellent characteristics, for example, having remarkably eminent physical characteristics including weather-resistance, aging-resistance and ozone-resistance and are highly durable to a broad temperature range when actually used, as compared with natural rubbers (NR) and other various kinds of synthetic rubbers such as styrene-butadiene copolymer rubbers (SBR), polybutadiene rubbers (BR), isobutylene-isoprene copolymer rubbers (IIR), polychloroprene rubbers (CR), acrylonitrile-butadiene copolymer rubbers (NBR) and polyisoprene rubbers (IR) or various kinds of synthetic resins such as ABS resins, polystyrene resins (PS), acrylonitrile-styrene copolymer resins (AS) and ethylene-vinyl acetate copolymer resins (EVA).
However, it has been known that, when a coating material or an adhesive is applied to the surface of a base made from a raw material polymer of the above-described polyolefin-type vulcanized rubbers such as EPDM or EPM or polyolefin-type synthetic resins such as PP or PE, the coated film is apt to be peeled off with ease from the surface of the base, since these polymers have no polar group in the main chain of the molecule.
Further, it has also been known that the adhesion of the paint material or adhesive as coated on the surface of a base made from a synthetic resin such as vinyl chloride resin, which contains a large amount of a plasticizer, gradually lowers as the plasticizer incorporated therein moves up to the surface of the base, after used for a long period of time.